Solvent-free film-forming compositions, coated substrates and method related thereto

Abstract

An aqueous dispersion including polymeric microparticles which are prepared in a medium substantially free of organic solvent from a mixture of one or more reaction products of polymerizable, ethylenically unsaturated monomers, and one or more reactive organopolysiloxanes is provided. Pigmented film-forming compositions, curable compositions and topcoats of multi-component composite coating composition containing the above-described dispersions also are provided. The substantially solvent-free film-forming compositions of the invention are storage stable at room temperature and provide coatings with excellent application properties such as sag resistance and tack-free overspray, and excellent performance properties such as hardness and scratch resistance. The film-forming compositions are suitable for wet-on-wet application over a base coat with little or no mudcracking.

Therefore we claim:  
     
       1. An aqueous dispersion comprising polymeric microparticles comprising the following components: 
       (A) at least one functional group-containing reaction product of polymerizable, ethylenically unsaturated monomers;  
       (B) at least one reactive functional group-containing organopolysiloxane having the following structure (II) or (III):                    
       wherein m has a value of at least 1; each of (n+m) and (n+m′) ranges from 2 to 3; R is selected from the group consisting of H, OH and monovalent hydrocarbon groups bonded to the silicon atoms; and R a  comprises the following structure (IV):  
       
         
           R 1 —X  (IV)  
         
       
       wherein R 1  is alkylene, oxyalkylene or alkylene aryl; and X comprises a functional group-containing moiety; and  
       (C) at least one hydrophobic crosslinking agent comprising functional groups reactive with the functional groups of (A) and/or (B), said hydrophobic crosslinking agent comprising at least one compound selected from blocked isocyanates, aminoplast resins, and mixtures thereof.  
     
     
       2. The dispersion of  claim 1 , wherein the polymeric microparticles are prepared in a medium substantially free of organic solvent. 
     
     
       3. The dispersion of  claim 1 , wherein the polymeric microparticles contain functional groups selected from the group consisting of hydroxyl, carbamate, carboxylic acid, isocyanate and blocked isocyanate, primary amine, secondary amine, amide, urea, urethane, alkoxysilane, vinyl and epoxy groups and mixtures thereof. 
     
     
       4. The dispersion of  claim 1 , wherein component (A) comprises the reaction product of the following reactants: 
       (i) at least one carboxylic acid functional group-containing, ethylenically unsaturated monomer; and  
       (ii) at least one ethylenically unsaturated monomer which is free of carboxylic acid functional groups.  
     
     
       5. The dispersion of  claim 4 , wherein reactant (i) is selected from the group consisting of (meth)acrylic acid, acryloxypropionic acid, crotonic acid, fumaric acid, monoalkyl esters of fumaric acid, maleic acid, monoalkyl esters of maleic acid, itaconic acid, monoalkyl esters of itaconic acid and mixtures thereof. 
     
     
       6. The dispersion of  claim 4 , wherein reactant (ii) is selected from the group consisting of alkyl esters of (meth)acrylic acid, vinyl aromatic monomers, acrylamides, acrylonitriles, dialkyl esters of maleic acid and fumaric acid, vinyl halides, vinyl acetate, vinyl ethers, allyl ethers, allyl alcohols, derivatives thereof and mixtures thereof. 
     
     
       7. The dispersion of  claim 6 , wherein the reactant (ii) comprises a hydroxyalkyl ester of (meth)acrylic acid. 
     
     
       8. The dispersion of  claim 4 , wherein the reactant (ii) comprises an ethylenically unsaturated beta-hydroxy ester functional monomer. 
     
     
       9. The dispersion of  claim 8 , wherein the beta-hydroxy ester functional monomer comprises the reaction product of reactants selected from the group consisting of: 
       (a) an ethylenically unsaturated, epoxy functional monomer and a saturated carboxylic acid having from 13 to 20 carbon atoms; and  
       (b) an ethylenically unsaturated, acid functional monomer and an epoxy compound containing at least 5 carbon atoms which is not polymerizable with the ethylenically unsaturated acid functional monomer.  
     
     
       10. The dispersion of  claim 1 , wherein the reaction product (A) is formed by free radical polymerization in the presence of the organopolysiloxane (B). 
     
     
       11. The dispersion of  claim 1 , wherein the reaction product (A) has an acid value ranging from 2 to 50 mg KOH/g. 
     
     
       12. The dispersion of  claim 1 , wherein the reaction product (A) is present in the dispersion in an amount ranging from 10 to 90 weight percent based on total weight of resin solids weight present in the dispersion. 
     
     
       13. The dispersion of  claim 1 , wherein the reactive organopolysiloxane (B) is substantially hydrophobic. 
     
     
       14. The dispersion of  claim 1 , wherein the reactive organopolysiloxane (B) contains reactive functional group selected from the group consisting of hydroxyl, carboxylic acid, isocyanate and blocked isocyanate, primary amine, secondary amine, amide, carbamate, urea, urethane, alkoxysilane, vinyl and epoxy functional groups and mixtures thereof. 
     
     
       15. The dispersion of  claim 1 , wherein X comprises at least one functional group selected from the group consisting of hydroxyl, carboxylic acid, isocyanate and blocked isocyanate, primary amine, secondary amine, amide, carbamate, urea, urethane, alkoxysilane, vinyl, and epoxy functional groups and mixtures thereof. 
     
     
       16. The dispersion of  claim 1 , wherein X comprises functional groups selected from the group consisting of hydroxyl groups, carbamate groups, and mixtures thereof. 
     
     
       17. The dispersion of  claim 1 , wherein the reactive orga opolysiloxane (B) is present in the dispersion in an amount ranging from 1 to 70 weight percent based on total weight of resin solids present in the dispersion. 
     
     
       18. The dispersion of  claim 1 , wherein the polymeric microparticles are internally crosslinked. 
     
     
       19. The dispersion of  claim 1 , wherein the crosslinker (C) is present in the dispersion in an amount ranging from 5 to 70 weight percent based on total weight of resin solids present in the dispersion. 
     
     
       20. The dispersion of  claim 1 , further comprising substantially inorganic microparticles ranging in size from 1 to 1000 nanometers prior to incorporation into the dispersion. 
     
     
       21. The dispersion of  claim 20 , wherein the inorganic microparticles are selected from the group consisting of fumed silica, amorphous silica, colloidal silica, alumina, colloidal alumina, titanium dioxide, zirconia, colloidal zirconia, and mixtures thereof. 
     
     
       22. A curable composition comprising: 
       an aqueous dispersion of polymeric microparticles, said microparticles having a functionality adapted to react with a crosslinking agent and being prepared in a medium substantially free of organic solvent from a mixture of the following components:  
       (1) at least one reaction product of polymerizable, ethylenically unsaturated monomers;  
       (2) at least one reactive functional group-containing organopolysiloxane having the following structure (II) or (III):                    
       wherein m has a value of at least 1; each of (n+m) and (n+m′) ranges from 2 to 3; R is selected from the group consisting of H, OH and monovalent hydrocarbon groups bonded to the silicon atoms; and R a  comprises the following structure (IV):  
       
         
           R 1 —X  (IV)  
         
       
       wherein R 1  is alkylene, oxyalkylene or alkylene aryl; and X comprises a functional group-containing moiety; and  
       (3) at least one hydrophobic crosslinking agent having reactive functional groups, said hydrophobic crosslinking agent comprising at least one compound selected from blocked isocyanates, aminoplast resins, and mixtures thereof, wherein components (1) and/or (2) contain functional groups reactive with the functional groups of (3).  
     
     
       23. The curable composition of  claim 22 , wherein the polymeric microparticles contain functional groups selected from the group consisting of hydroxyl, carbamate, carboxylic acid, isocyanate and blocked isocyanate, primary amine, secondary amine, amide, urea, urethane, alkoxysilane, vinyl and epoxy groups and mixtures thereof. 
     
     
       24. The curable composition of  claim 22 , wherein component (1) comprises acid functional groups. 
     
     
       25. The curable composition of  claim 24 , wherein component (1) comprises the reaction product of the following reactants: 
       (A) at least one carboxylic acid functional group-containing, ethylenically unsaturated monomer; and  
       (B) at least one ethylenically unsaturated monomer which is free of carboxylic acid functional groups.  
     
     
       26. The curable composition of  claim 25 , wherein the reactant (B) comprises a hydroxyalkyl ester of (meth)acrylic acid. 
     
     
       27. The curable composition of  claim 25 , wherein the reactant (B) comprises an ethylenically unsaturated beta-hydroxy ester functional monomer. 
     
     
       28. The curable composition of  claim 27 , wherein the beta-hydroxy ester functional monomer comprises the reaction product of reactants selected from the group consisting of: 
       (a) an ethylenically unsaturated, epoxy functional monomer and a saturated carboxylic acid having from 13 to 20 carbon atoms; and  
       (b) an ethylenically unsaturated, acid functional monomer and an epoxy compound containing at least 5 carbon atoms which is not polymerizable with the ethylenically unsaturated acid functional monomer.  
     
     
       29. The curable composition of  claim 22 , wherein the reaction product (1) is present in the dispersion in an amount ranging from 20 to 90 weight percent based on total weight of resin solids present in the dispersion. 
     
     
       30. The curable composition of  claim 22 , wherein the reactive organopolysiloxane (2) is substantially hydrophobic. 
     
     
       31. The curable composition of  claim 22 , wherein the reactive organopolysiloxane (2) contains reactive functional group selected from the group consisting of hydroxyl, carbamate, carboxylic acid, isocyanate and blocked isocyanate, primary amine, secondary amine, amide, urea, urethane, alkoxysilane, vinyl, and epoxy functional groups and mixtures thereof. 
     
     
       32. The curable composition of  claim 1 , wherein X comprises at least one functional group selected from the group consisting of hydroxyl, carboxylic acid, isocyanate and blocked isocyanate, primary amine, secondary amine, amide, carbamate, urea, urethane, alkoxysilane, vinyl and epoxy functional groups and mixtures thereof. 
     
     
       33. The curable composition of  claim 1 , wherein X comprises functional groups selected from the group Consisting of hydroxyl groups, carbamate groups and mixtures thereof. 
     
     
       34. The curable composition of  claim 22 , wherein the reactive organopolysiloxane (2) is present in the dispersion in an amount ranging from 1 to 70 weight percent based on total weight of resin solids present in the dispersion. 
     
     
       35. The curable composition of  claim 22 , wherein the crosslinker (3) is present in the dispersion in an amount ranging from 5 to 70 weight percent based on total weight of resin solids present in the dispersion. 
     
     
       36. The curable composition of  claim 22 , further comprising at least one hydrophilic crosslinking agent reactive with the functionality of the microparticles. 
     
     
       37. The curable composition of  claim 22 , further comprising substantially inorganic microparticles ranging in size from 1 to 1000 nanometers prior to incorporation into the curable composition. 
     
     
       38. The curable composition of  claim 37 , wherein the iorganic microparticles are selected from the group consisting of fumed silica, amorphous silica, colloidal silica, alumina, colloidal alumina, titanium dioxide, zirconia, colloidal zirconia, and mixtures thereof. 
     
     
       39. The curable composition of  claim 22 , further comprising at least one pigment.